On February 16, 2008, while en route from Bayonne, New Jersey, on a nine-day cruise to the Caribbean the bridge crew heard a faint mayday call over the radio. This turned out to be the crew from Tumbleweed, a 39-foot sailing vessel,[12] which had a planned sail from Baltimore to the Florida Keys. The crew reportedly had a mechanical breakdown of both engine and sails. The vessel drifted for 11 days to the location N32.35 W 72.49–roughly 275 miles southeast of North Carolina. Explorer of the Seas located and rescued the three men, who then departed the ship in Puerto Rico on February 21, 2008.[12]

On May 5, 2010, 26-year-old bartender Satianand Buddaru was caught on surveillance jumping overboard. The ship turned around to rescue him but was unable to locate the bartender.[13][unreliable source?]

On January 24, 2014, 281 passengers and 22 crew members aboard Explorer of the Seas fell ill, reporting symptoms of vomiting and diarrhea. Due to the number of passengers sick, the Centers for Disease Control and Prevention sent a Sanitation Program Officer and an epidemiologist to the ship on Sunday, January 26, 2014, when it was docked in St. Thomas.[15] By 27 January 2014 the number of ill increased to 564 passengers and 47 crew members and a decision was made to end the cruise early.[16] After Explorer of the Seas returned to port, 684 of the 4,237 aboard had symptoms of norovirus.[17]

On December 16, 2015, A total of 182 passengers out of the 3566 on board Explorer of the Seas contracted infectious diarrhea. The ship’s operator contacted South Eastern Sydney Local Health District before arriving in Sydney at 6am. None of the passengers were taken to hospital.[18]